DE102016225444A1 - Improved media distribution in fuel cell stacks - Google Patents

Abstract

The invention relates to a fuel cell stack (20) with at least two, in particular identical, fuel cells (12), which are designed in particular as bipolar plates (10) and which are stacked on top of each other, wherein the fuel cells (12) via at least one bus (24) with the same Cross-section fluidly connected to each other, in particular recesses (16) with the same cross-section, which are part of the bipolar plates (10), the manifolds form. It is proposed to arrange at least one insert element (28) in the collecting line (24) into which at least one flow opening (30) for at least one of the fuel cells (12) is introduced. The invention also relates to a method for producing such an insert element (28) for a fuel cell stack (20).

Description

The present invention relates to fuel cell stack with at least two, in particular identical, fuel cells, which are in particular designed as bipolar plates, and which are stacked, the fuel cells are fluidly connected to each other via at least one manifold with the same cross section, in particular recesses with the same cross section, the part which are bipolar plates that form manifolds. The invention also relates to a method for producing an insert element for such a fuel cell stack.

State of the art

The document DE 10 2014 220 682 A1 discloses a fuel cell stack with a manifold, wherein an insert element is insertable into the manifold, with which the cross section of the manifold is at least partially variable.

Disclosure of the invention

The present invention has the advantage that at least one insert element is arranged in the manifold, in which at least one flow opening for at least one of the fuel cells is introduced, whereby an intake and / or removal of fluid can be directly influenced for the at least one fuel cell ,

The features listed in the dependent claims advantageous developments of the invention according to the main claim are possible. Thus, it is conceivable that a large number of flow openings is introduced into the insert element, wherein in each case at least one flow opening is assigned in each case to a fuel cell. Thus, an inflow and / or outflow of fluid can be influenced directly at each individual fuel cell of the fuel cell stack.

It is advantageous if different flow openings, in particular along the manifold, have different cross sections, whereby the supply and / or removal of fluid can be designed differently on each individual fuel cell.

It is particularly advantageous if the size of the cross sections of the respective flow openings increases with a supply of fluid in the flow direction along the collecting line and / or decreases during a discharge of fluid in the flow direction along the collecting line. Thus, the amount of flowing fluid can be almost equally distributed to all fuel cells.

It is preferred if the insert element is arranged on a side facing the fuel cell, in particular on a wall of the manifold facing the fuel cell, whereby a particularly effective influencing of the supply and / or removal of fluid can take place.

In a preferred embodiment, at least one guide element, in particular directly in and / or at the at least one flow opening, is formed in and / or on the at least one insert element. Thus, the flow of added and / or discharged fluid can be additionally influenced.

In a further advantageous embodiment, a further insert element is arranged in the manifold, whereby an additional influence on the supply and / or discharge of fluid is made possible.

It is particularly preferred if the further insert element is arranged on a side facing away from the fuel cell side, in particular on a side remote from the fuel cell wall of the manifold, whereby a particularly effective, additional influence on the supply and / or removal of fluid can take place.

It is particularly advantageous if at least one guide element, in particular opposite of at least one flow opening, is formed on the at least one further insert element, whereby the supply and / or removal of fluid can additionally be improved.

The invention also relates to a method for producing at least one insert element for a fuel cell stack according to the preceding description. The method is characterized in that at least one flow opening is introduced into the insert element, in particular by means of a stamping method, wherein at least one further guide element, preferably directly in and / or at the at least one flow opening, is formed by introducing the flow opening. As a result, a cost-effective production of the insert element for a fuel cell stack is made possible.

list of figures

• 1 eine schematische Darstellung einer als Bipolarplatte ausgestalteten Brennstoffzelle,
• 2 eine schematische, perspektivische Ansicht von übereinander gestapelten Bipolarplatten aus 1 mit zusätzlicher Medienleitung,
• 3 eine schematische Darstellung eines Querschnitts eines Brennstoffzellenstacks,
• 4 eine schematische, perspektivische Ansicht eines Ausführungsbeispiels eines Brennstoffzellenstacks mit einem Einlegeelement,
• 5 eine schematische Darstellung eines Querschnitts des Ausführungsbeispiels eines Brennstoffzellenstacks mit einem Einlegeelement aus 4,
• 6 eine schematische Darstellung eines Querschnitts eines weiteren Ausführungsbeispiels eines Brennstoffzellenstacks mit einem Einlegeelement,
• 7 eine schematische Darstellung eines Querschnitts eines weiteren Ausführungsbeispiels eines Brennstoffzellenstacks mit einem Einlegeelement und einem weiteren Einlegeelement,
• 8 eine schematische Darstellung eines Querschnitts eines weiteren Ausführungsbeispiels eines Brennstoffzellenstacks mit nur einem weiteren Einlegeelement.

In the drawings, embodiments of the invention are shown schematically and explained in more detail in the following description. Show it

• 1 a schematic representation of a configured as a bipolar plate fuel cell,
• 2 a schematic perspective view of stacked bipolar plates from 1 with additional media line,
• 3 a schematic representation of a cross section of a fuel cell stack,
• 4 1 is a schematic, perspective view of an embodiment of a fuel cell stack with an insert element,
• 5 a schematic representation of a cross section of the embodiment of a fuel cell stack with an insert element 4 .
• 6 FIG. 2 a schematic illustration of a cross section of a further exemplary embodiment of a fuel cell stack with an insert element, FIG.
• 7 FIG. 2 a schematic representation of a cross section of a further exemplary embodiment of a fuel cell stack with an insert element and a further insert element, FIG.
• 8th a schematic representation of a cross section of another embodiment of a fuel cell stack with only one further insert element.

description

In the different figures, the same components or components are always provided with the same reference numerals, which is why they are usually described only once.

In 1 is a schematic representation of a bipolar plate 10 designed fuel cell 12 shown. The hatched area represents the active area 14 the bipolar plate 10. On the active surface 14 are, for example, the membrane electrode units. Left and right of the active area 14 are each two overlapping recesses 16 designed as supply openings 18 serve. The bipolar plate 10 is designed as a common part to keep the cost of production as low as possible. The as recesses 16 designed supply openings 18 serve the supply and / or discharge of at least one fluid, in the embodiments shown fuel gas, air and cooling medium. Like in the 1 can be seen, have the configured as a supply opening recesses 16 a cross-section, due to the Gleichbauweise the bipolar plates 10 always the same.

In the 2 are several similar to the one in 1 shown bipolar plates 10 to a fuel cell stack 20 stacked. Unlike in the 1 shown bipolar plate 1 have the in the 2 to a fuel cell stack 20 stacked bipolar plates 10 an additional recess 22 on, for example, the supply and / or removal of a cooling medium in the bipolar plates 10 serves. The recesses 16 and 22 form due to the Gleichbauweise the bipolar plates 10 each common bus lines 24 from, by the at least one fluid, for example. Fuel gas, air or cooling medium to the individual fuel cells bipolar plates 10 of the fuel cell stack 20 be directed. Because the bipolar plates 10 and therefore also as recesses 16 designed supply openings 18 are designed in identical part design, have the manifolds 24 in the sequence of bipolar plates 10 in the fuel cell stack 20 always the same, ie an unchanged cross section.

In 3 is a schematic representation of a cross section of a fuel cell stack 20 is shown. The fuel cell stack 20 has a plurality of, in particular identical, fuel cells 12 on, which are configured in the embodiment shown as bipolar plates 10, and which are stacked one above the other. There are between the fuel cells 12 , or bipolar plates 10 , Seals 26 arranged. The fuel cells 12, and the bipolar plates 10 , are about at least one bus 22 fluidly interconnected with the same cross-section, in particular recesses 16 with the same cross-section, the part of the bipolar plates 10 are that form manifolds.

The present invention is characterized in that an insert element 28 in at least one of the manifolds 24 is arranged, in which at least one flow opening 30 for at least one of the fuel cells 12 , or the bipolar plates 10 , is introduced. As a result, the supply and / or removal of fluid for at least one of the fuel cells 12 , or the bipolar plates 10 , to be influenced.

Accordingly, in 4 a schematic, perspective view of an embodiment of a fuel cell stack 20 with an insert element 28 shown. The insert element 28 will be in the manifold 24 inserted, via which the fuel cells 12 , or the bipolar plates 10 , Air is supplied.

In the embodiment shown is in the insert element 28 a variety of flow openings 30 introduced, wherein in each case a flow opening 30 each of a fuel cell 12 , or a bipolar plate 10 , assigned. So can supply of air for each fuel cell 12 , or each bipolar plate 12 , be influenced separately.

The different flow openings 30 point along the manifold 24 , different cross sections. This allows the supply of air specific to each fuel cell 12 be adjusted.

How to get the 4 can take the size of the cross sections of the respective flow openings takes 30 with a supply of fluid in the flow direction along the manifold 24 to. So the flow resistance at the entrance to the individual fuel cells 12 in the flow direction along the manifold 12 gradually reduced, ensuring a uniform distribution of the supplied air over all fuel cells 12 is achieved.

Likewise, it is conceivable the insert element in a manifold 24 to insert, via which a fluid, for example, already reduced air or exhaust gas, is discharged. Thus, it would also be conceivable that with a discharge of fluid, the size of the cross sections of the respective flow openings 30 in the flow direction along a manifold 30 decreases, whereby a uniform discharge is achieved.

5 shows a schematic representation of a cross section of the embodiment of the fuel cell stack 20 with the insert element 28 out 4 , So it can be seen that the insert element 28 at one of the fuel cells 12 facing side, or at one of the fuel cells 12 facing wall of the manifold 24 , is arranged. As a result, the flow of the supplied air directly at the entrance of each fuel cell can be specifically influenced. In addition, a mounting of the insert element 28 simplified, as this along the wall of the manifold 24 can be introduced into the fuel cell stack.

In 6 is a schematic representation of a cross section of another embodiment of a fuel cell stack 20 with an insert element 28 shown. It can be seen that on the insert element 28 guide elements 32 , In the case shown directly at the flow openings 30 , are formed. By means of the guide elements 32 can the flow for any fuel cell 12 be additionally optimized. So can the length, shape and inclination of the guide elements 32 for every fuel cell 12 be varied.

In 7 is a schematic representation of a cross section of another embodiment of a fuel cell stack 20 with an insert element 28 shown. In the embodiment, another insert element 34 in the manifold 24 introduced, whereby an additional optimization of the flow is made possible.

The further insert element 34 is at the of the fuel cells 12 opposite side, in the case shown at the of the fuel cells 12 facing away from the wall of the manifold 24 arranged. This is how the further insert element can be arranged 34 simply insert it into the fuel cell stack.

In addition, at the other insert element 34 further guide elements 36 in the case shown opposite from the flow opening 30 , educated. Through the other guide elements 34 the flow can be supportive to the guiding elements 32 for every fuel cell 12 influenced and optimized.

Alternatively, it is also conceivable that in a further embodiment, only the further guide element 34 in the manifold 24 is introduced. Accordingly, in 8th a schematic representation of a cross section of another embodiment of a fuel cell stack 20 with only one more insert element 34 shown. It is also conceivable that the insert element 28 at the of the fuel cells 12 opposite side, in the case shown at the of the fuel cells 12 facing away from the wall of the manifold 24 , is arranged.

Moreover, the invention also relates to a method for producing the insert element 28 for a fuel cell stack 20 , The method is characterized in that the flow openings 30 in the insert element 28 are introduced, wherein by introducing the flow openings 30 the guide elements 32 be formed. This allows the guide elements 32 simultaneously with the introduction of the flow openings 30 training, thereby saving costs in the production.

For the in 6 and 7 The embodiments shown are the flow openings 30 by means of a punching process in the insert element 28 introduced, wherein by punching out the flow openings 30 the guide elements 32 be formed. In the cases shown, the guide elements 32 while directly in or at the flow openings 30 educated.

For the in 8th embodiment shown are the other guide elements 36 to the further insert element 34 welded.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102014220682 A1 [0002]

Claims (10)

Fuel cell stack (20) with at least two, in particular identical, fuel cells (12) which are in particular designed as bipolar plates (10), which are stacked on top of each other, wherein the fuel cells (12) via at least one manifold (24) with the same cross section fluidly connected to each other wherein in particular recesses (16) of substantially equal cross-section, which are part of the bipolar plates (10), the manifolds, characterized in that at least one insert element (28) in the manifold (24) is arranged, in which at least one flow opening (30) is introduced for at least one of the fuel cells (12). Fuel cell stack (20) according to any one of the preceding claims, characterized in that in the insert element (28) a plurality of flow openings (30) is introduced, wherein in each case at least one flow opening (30) is associated with each of a fuel cell (12). Fuel cell stack (20) according to one of the preceding claims, characterized in that different flow openings (30), in particular along the manifold (24), have different cross-sections. Fuel cell stack (20) after Claim 3 , characterized in that the size of the cross sections of the respective flow openings (30) increases with a supply of fluid in the flow direction along the collecting line (24) and / or decreases with a discharge of fluid in the flow direction along the collecting line (24). Fuel cell stack (20) according to any one of the preceding claims, characterized in that the insert element (28) on a fuel cell (12) facing side, in particular on a fuel cell (12) facing wall of the manifold (24) is arranged. Fuel cell stack (20) according to any one of the preceding claims, characterized in that in and / or on the at least one insert element (28) at least one guide element (32), in particular directly in and / or on the at least one flow opening (30) is formed , Fuel cell stack (20) according to one of the preceding claims, characterized in that a further insert element (34) is arranged in the collecting line (24). Fuel cell stack (20) according to any one of the preceding claims, characterized in that the further insert element (34) on one of the fuel cells (12) facing away from, in particular on a side remote from the fuel cell (12) wall of the manifold (24) is arranged , Fuel cell stack (20) according to one of the preceding claims, characterized in that on the at least one further insert element (34) at least one further guide element (36), in particular opposite of at least one flow opening (30) is formed. A method for producing at least one insert element (28) for a fuel cell stack (20) according to any one of the preceding claims, characterized in that in the insert element (28), in particular by means of a punching process, at least one flow opening (30) is introduced, wherein the introduction at least one guide element (32), preferably directly in and / or at the at least one flow opening (30), is formed in the flow opening (30).

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